Giving Boris a prominent role in the campaign may not have a dramatic effect on the election result, but if the Tories are going to win enough seats to form a government (especially in London), they need to use every asset at their disposal.

When Boris won the mayoral election, he outperformed the Tory vote in the simultaneous local elections. While it’s true that London mayoral elections tend to reward charisma more than national elections, his victory highlighted his appeal to voters beyond party lines.

The question for David Cameron will be how to use Boris most effectively without undermining his own position or creating the impression that his party leadership is being usurped. This shouldn’t be difficult: giving Boris a prominent media-facing role would strengthen the Tory team and would only be a problem for Cameron if the Conservatives fail to win enough seats to form a government – at which point he’d have to stand down anyway.

Charlie Cadywould, a researcher at the think tank Demos, says No

There’s no doubt that Boris has his charms: any Tory capable of winning in Labour-leaning London while remaining the darling of his party’s right wing clearly has some appeal. However, no individual other than the party leader can swing an election.

The Conservatives have a brand problem: they’re seen by many as the party of the privileged, and Boris’s addition to the team will do nothing to assuage voters’ concerns that the party doesn’t care as much about ordinary people. The Tories need to show that they care through policies – not personalities. Immigration and the NHS have replaced the economy as the top concerns of most voters, and their salience should trouble Conservative strategists.

To win, they need to keep the economy relevant – which is where Labour trails the Tories in the polls. Showing how a Tory government can balance the budget and deliver growth the whole country feels, while safeguarding public services, is the key challenge Cameron faces.